Beckenham Place Clubhouse as Asylum
Dr. Julia Hoffman (Helena Bonham Carter) escapes from the asylum by bedsheets. Check out the filming of the scene on youtube.
Dark Shadows Filming Locations
Interiors were filmed at Pinewood studios and exteriors were built specifically for the film in Surrey. You can check out photos of the building of Collinwood Mansion here
Dark Shadows was filmed in London in the United Kingdom.